1. Field of the Invention
The invention relates to food products having a conserved or enhanced content of cocoa polyphenols and processes for producing the same. The food products prepared by the processes of this invention include edible food products, confectionery products and standard of identity and non-standard of identity chocolate products, and the like, having conserved concentrations of cocoa polyphenols therein.
2. Related Background Art
Polyphenolic compounds are bioactive substances that are derived from plant materials and are closely associated with the sensory and nutritional quality of products derived from these plant materials. The term "cocoa polyphenol" includes the polyphenolic products, including proanthocyanidins, and more particularly procyanidins, extracted from cocoa beans and derivatives thereof. More specifically, the term "cocoa polyphenol" includes monomers of the formula A.sub.n (where n is 1) or oligomers of the formula A.sub.n (where n is an integer from 2 to 18, and higher), wherein A has the formula: ##STR1##
and R is 3-(.alpha.)--OH, 3-(.beta.)--OH, 3-(.alpha.)--O-saccharide, 3-(.beta.)--O-saccharide, 3-(.alpha.)--O--C(O)--R', or 3-(.beta.)--O--C(O)--R'; PA1 bonding between adjacent monomers takes place at positions 4, 6 or 8; PA1 a bond to a monomer in position 4 has alpha or beta stereochemistry; PA1 X, Y and Z are selected from the group consisting of A, hydrogen, and a saccharide moiety, with the provisos that as to at least one terminal monomer, bonding of the adjacent monomer thereto is at position 4 and optionally Y.dbd.Z.dbd.hydrogen; and PA1 wherein the saccharide moiety is a mono- or di-saccharide moiety and may be optionally substituted with a phenolic moiety and R' may be an aryl or heteroaryl moiety optionally substituted with at least one hydroxyl group; and PA1 salts, derivatives and oxidation products thereof. PA1 (a) mixing at least one ingredient of the product with at least one polyphenol-conserving pre-treatment ingredient to form a mix, PA1 (b) combining the mix with at least one ingredient containing cocoa polyphenol, and PA1 (c) forming the polyphenol-containing product, wherein the product contains at least about 10% by weight more polyphenol than a product prepared without using the pre-treatment process according to step (a).
Advantageously, the saccharide moiety is derived from the group consisting of glucose, galactose, xylose, rhamnose and arabinose. The saccharide moiety and any or all of R, X, Y, and Z may optionally be substituted at any position with a phenolic moiety via an ester bond. The phenolic moiety is selected from the group consisting of caffeic, cinnamic, coumaric, ferulic, gallic, hydroxybenzoic and sinapic acids.
Many plant polyphenols have antioxidant activity and have an inhibitory effect on mutagenesis and carcinogenesis. Cocoa polyphenol extracts, particularly procyanidins, have recently been shown to possess significant biological utility. Particularly, WO 97/36497 discloses that these extracts also function to reduce periodontal disease, atherosclerosis and hypertension, inhibit LDL oxidation and DNA topoisomerase II, modulate cyclo-oxygenase, lipoxygenase, nitric oxide or NO-synthase, apoptosis, platelet aggregation, and possess anti-inflammatory, antigingivitis and antiperiodontis activity. Moreover, WO 97/36497 discloses that oligomers 5-12 possess the highest anti-cancer activity of the polyphenolic compounds isolated from cocoa. Thus, consumption of these higher oligomers in cocoa products may provide significant health benefits. Accordingly, food products, such as confectioneries and cocoa-containing products (cocoa powders, chocolate liquors, or extracts thereof) having a high cocoa polyphenol concentration, especially a high concentration of cocoa polyphenol oligomers 5-12, would be especially desirable.
The cocoa polyphenol extracts, or compounds further separated therefrom, have generally been prepared, on a laboratory scale, by reducing cocoa beans to a powder, defatting the powder, and extracting and purifying the active compound(s) from the defatted powder. The powder is generally prepared by freeze-drying the cocoa beans and pulp, de-pulping and de-shelling the freeze-dried beans and grinding the de-shelled beans or nibs. The extraction of active compound(s) has been accomplished by solvent extraction techniques, and the extracts have been purified by gel permeation chromatography, preparative high performance liquid chromatography (HPLC) techniques, or by a combination of such methods, as disclosed in Romanczyk et al., U.S. Pat. No. 5,554,645.
Under-fermented and unfermented cocoa raw materials contain substantial amounts of cocoa polyphenols, compared to fermented cocoa. Fermentation and drying bring about complex changes in the cocoa bean, most notably, the formation of components required for the development of the characteristic flavor and color of cocoa. Fermentation, however, also significantly decreases the concentrations of polyphenolic compounds in the fermented cocoa beans, relative to the concentrations of polyphenolic compounds in unfermented or under-fermented beans. Traditional cocoa bean processing, including such steps as roasting or de-fatting of the cocoa beans, also reduces the cocoa polyphenol concentration in the cocoa powder or chocolate liquors produced thereby. Moreover, these processes reduce the concentrations of higher oligomeric polyphenols (oligomers 5-12) more rapidly than lower oligomers (2-4) or monomers. Accordingly, it was highly desirable to develop methods of conserving or retaining the higher oligomers that not only possessed more significant biological activity than lower oligomers, but also appeared to be more sensitive to processing conditions than the lower oligomers.
Accordingly, it would be highly desirable to develop processing techniques to prepare food products and confectioneries, particularly cocoa-containing confectioneries, that will conserve the cocoa polyphenol concentration of cocoa powders, chocolate liquors, or extracts thereof, in the finished, shelf-ready product.